Mounting device for abrasive wheels

ABSTRACT

A reusable mount for an abrasive device ( 14 ) including a nut ( 12 ) and a support unit ( 10 ). The nut ( 12 ) includes a threaded barrel ( 20 ) and a flange ( 22 ). The barrel extends through a central opening ( 15 ) in the abrasive device and the support unit it threadably attached by hand to the barrel to capture the abrasive device between the flange and the support unit. The assembled abrasive device and mount are then threadably secured to the spindle ( 70 ) of a power tool for use.

CROSS-REFERENCE TO RELATED APPLICATION

The benefits of Provisional Application No. 60/323,288 files Sep. 19,2001 by Joseph H. MacKay for MOUNTING DEVICE FOR ABRASIVE WHEELS andProvisional Application No. 60/388,147 filed May 17, 2002 by Joseph H.MacKay for IMPROVEMENT FOR MOUNTING DEVICE FOR ABRASIVE WHEELS is herebyclaimed.

FIELD OF THE INVENTION

This invention relates generally to abrasive articles useful forgrinding, cutting and finishing and more particularly to a reusablemount for attaching such articles to a power tool adapted for rotatingthe article during use.

BACKGROUND OF THE INVENTION

The use of rotatably driven abrasive articles for grinding, cutting andfinishing work objects is widespread and very familiar in our industrialsocieties. Early on, such abrasive articles were affixed to portablerotary power tools such as air motors or the like by placing aninternally threaded nut through a centrally located opening in theabrasive article. The nut included a hub portion which fitted into thebore so that a head or flange portion of the nut abutted the undersideof the abrasive article. The nut is adapted to be mounted to thethreaded spindle of the power tool. Typically a support flange ispositioned on the spindle of the power tool between the abrasive articleand an annular shoulder formed on the spindle to provide backing supportfor the abrasive article. Typically the support is made of a metalstamping that is configured to engage the backside of the abrasivearticle. The direction of rotation of the spindle when the rotary motoris energized is such that the nut will self thread onto the spindleuntil a tight frictional engagement is provided. Typically the abrasivearticle when it is spent is removed from the spindle by applying awrench to the nut. The nut in the prior art conventional assemblies isnot permanently affixed to the abrasive article, but rather is intendedto be reused when a worn abrasive article is replaced. Also the supportflange is not permanently affixed to the abrasive article and also isintended to be reused with new disks. Typical of such prior art abrasivefinishing devices and the means of attachment to the power tool areshown in U.S. Pat. Nos. 489,149; 3,596,415; 1,998,919; 566,883; 507,223;1,162,970; 791,159; 489,149 and 3,210,892.

With these earlier prior art devices, which included the flange and nut,it was very difficult to remove the spent finishing article because ofthe extreme forces applied to it during operation of the power tool. Asabove indicated, such removal required the utilization of a wrench orother tool which expended a large amount of time and effort on the partof the user.

Subsequently it became desirable to affix the mount permanently to theabrasive device so that the entire unit may be quickly and easilyattached and detached from the drive shaft of the power motor anddiscarded along with the abrasive article when the abrasive article hasbeen spent. In these types of devices it has become customary to eitherutilize an adhesive such as an epoxy resin or the like to attach themounting hub to the abrasive article or alternatively to crimp a portionof the mounting hub to the abrasive article to retain it permanently inplace upon the abrasive article and to secure the article rotationally.Various prior art patents showing such devices are U.S. Pat. Nos.3,136,100; 415,371; 2,278,301; 3,081,584; 3,500,592; 3,800,483;4,240,230; 4,541,205; 3,041,797; 3,879,178; 1,724,742; 3,912,411;3,879,178; 3,960,516; 4,026,074; 4,054,425; 4,088,729; 4,322,920;4,439,953; 4,449,329; 4,601,661; 791,791; 872,932; 2,567,782; 3,136,100;3,210,892; 3,621,621; 4,924,634; 5,287,659 and 4,760,670. With thesedevices, where a portion of the mounting structure is permanentlyaffixed to the abrasive article an additional cost is added to theabrasive article, because of the labor in attaching the mount and thediscarding of the permanently attached mounting structure.

As a result of the experience in the industry utilizing abrasivedevices, it became apparent that there was a need for a reusablemounting structure which will quickly and easily accept the abrasivearticle without being permanently attached in any fashion to theabrasive article and which at the same time will provide sufficientclamping to maintain the integrity of the abrasive article duringoperation while allowing easy removal of the abrasive article from thepower tool once it has been spent without the necessity of utilizingtools. Such a device is shown in U.S. Pat. No. 6,379,234 which includesa support unit defining a bore with a resiliently deformable memberdisposed therein which grips the barrel of a retainer nut to hold themount on the wheel for attachment to the power tool.

The foregoing devices work well for the purpose intended, however, itwas discovered that a reusable mount for abrasive devices which could bemore positively secured to the abrasive device was desirable. At thesame time the abrasive device when spent must be easily removable byhand from the power tool and the mount.

SUMMARY OF THE INVENTION

A reusable quick change mount for use with abrasive devices which areadapted for rotation by a rotary power tool which mount includes a nuthaving a barrel with a flange extending radially outward from one endthereof with the barrel adapted to be received within the centralopening of the abrasive device so that at least a portion of the flangeengages the abrasive device with a portion of the barrel extendingbeyond the abrasive device. The external surface of the barrel isthreaded. There is also included a support unit having a centrallydisposed threaded bore which matingly engages the threaded outer surfaceof the barrel to thereby capture the abrasive device between the flangeand the support unit. Threads are provided on the barrel that areadapted to matingly engage threads carried by the rotary power tool forrotation of the abrasive device during use. Once the nut and supportunit are snugly secured to the abrasive device by hand there issubstantially no relative movement between them during use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view in isometric form of the reusable quickchange mount of the present invention just prior to assembly with adepressed center grinding wheel;

FIG. 2 is a cross-sectional view of the nut utilized as one of thecomponents of the mount;

FIG. 3 is a cross-sectional view of the support unit which is the othercomponent of the mount;

FIG. 4 is a cross-sectional view of the quick change mount of thepresent invention assembled upon a depressed center grinding wheel readyto be attached to a threaded drive member of a rotary power tool;

FIG. 5 is a cross-sectional view of an alternative embodiment of thereusable mount of the present invention installed on a cut off wheel;

FIG. 6 is a cross-sectional view of an alternative embodiment of asupport unit of the present invention; and

FIG. 7 is a cross-sectional view of a further alternative embodiment ofa support unit of the present invention.

DETAILED DESCRIPTION

The reusable quick change mount constructed in accordance with theprinciples of the

present invention provides for vary rapid and easy attachment of anabrasive device such as a grinding wheel to a power tool. The mount istightened snugly by hand on the abrasive device before it isrotationally secured to the power tool. Such tightening is sufficient tosecure the abrasive device to the mount for use in cutting or finishingmetallic workpieces. After the abrasive device has been spent, the mountof the present invention is constructed in such a manner that very quickand easy removal of the spent abrasive device can be accomplished afterthe mount and abrasive device is removed from the power tool simply byrotation of the mount components by hand as opposed to utilizing toolssuch as wrenches or the like to loosen the mount.

The reusable quick change mount of the present invention is usable upona wide variety of abrasive devices such as grinding wheels, flap discs,cut-off wheels and the like and may be utilized upon such devices havingvery small to the largest diameters. The mount employs two componentsneither of which is permanently installed upon the abrasive device. Eachof the components is durable and reusable with large quantities ofabrasive devices. As a result, the cost of mounting hubs which arepermanently installed in a non-removable fashion upon abrasive devicesas well as the cost of installation thereof and the waste and pollutionassociated with the disposal of used abrasive devices containing suchpermanently installed mounting hubs thereon is totally eliminated.

The two components which form the reusable quick change mount of thepresent invention include a support unit which functions as a backingflange for the abrasive device during use and a threaded nut or retainermember which holds the abrasive device in place for use upon the powertool. The nut includes a barrel extending from a flange with the nutbeing inserted into the bore centrally disposed through the abrasivedevice in such a manner that a portion of the barrel projects throughthe abrasive device. The support unit has a threaded bore therethroughwhich threadably receives that part of the threaded barrel extendingbeyond the abrasive device and causing the abrasive device to becaptured between the support unit and the nut flange while the assemblyis being handled for quick and easy attachment to a power tool.

After use, typically when the abrasive device is spent, the user merelygrips the abrasive device and turns it in the counter clockwisedirection to quickly and easily remove the spent abrasive device alongwith the nut and support unit from the power tool after which thesupport unit and nut are disengaged simply by rotation to separate themand the abrasive device is discarded. The nut and support unit are thenready for reuse by being assembled to another abrasive device.

Referring now to the drawings and more particularly to FIGS. 1-3. Theconstruction of a preferred embodiment of the reusable quick changemount of the present invention is illustrated. As is therein shown, thetwo components of the mount are a support unit or backing member 10 anda nut or retainer member 12. An abrasive finishing article such as adepressed center grinding wheel 14 having a centrally disposed opening15 between the opposed surfaces 16 and 18 of the support unit 10 and thenut 12. The nut 12 includes a barrel 20 having a flange 22 extendingoutwardly from a first end 24 thereof The surface 18 is the uppersurface of the flange 22 and when assembled with an abrasive device willcontact that device. The nut 12 is formed preferably from a unitarymetallic work piece. The support unit 10 includes a body 26 having anupper knurled ridge 28 which facilitates gripping and holding of thesupport unit 10 during installation thereof upon an abrasive member. Awear or bearing surface 30 is also provided on the support unit 10. Thebearing surface 30 engages a shoulder which exists upon the drive memberof a power tool which is assembled with the reusable quick change mountof the present invention.

As is more clearly seen in FIG. 2, the nut 12 defines a bore 32extending through the barrel 20. The barrel 20 also includes an outersurface 36 which is also threaded as illustrated at 38. The bore 32 isthreaded as illustrated at 34.

The support member 10 as seen in FIG. 3 is constructed from a metallicbody 42 and includes a first surface 44 and a second surface 46. Themetallic body 42 may be any material desired and preferably is machinedsteel which defines a bore 48 extending therethrough. The bore 48defines threads as illustrated at 49. The threads 49 are adjusted tomatingly engage the threads 38 on the barrel 20 of the nut 12. Thebearing surface 30 may preferably comprise a washer like member of heattreated steel 50 which is secured to the first face 44 of the body 42.The face 44 is counter bored to provide a recess within which the washer50 is seated. The surrounding material on the face 44 is then stamped orupset to permanently secure the washer 50 in place. The wear surface 30provides a surface which will tolerate numerous uses of the support unit10 with various abrasive devices. Alternatively the washer 50 in somecircumstances may be constructed of a hard plastic material. As abovepointed out, when the reusable quick change mount of the presentinvention is assembled upon an abrasive device, the barrel 20 of the nut12 is inserted through the opening 15 of the abrasive device 14 with atleast some of the threads 20 extending beyond the top surface 17thereof. The support unit 10 is then assembled by threadably securing iton the threads 20 and snugly tightening it against the surface 17. Suchtightening securely holds the nut and the support unit firmly togetheron opposite sides of the abrasive article which is trapped between theflange 22 and the surface 46 while the combination is threaded upon thethreaded shaft of the power tool through utilization of the threads 34on the nut 12.

By reference now to FIG. 4, there is illustrated in partialcross-sectional view, the structure illustrated in FIG. 1 in assembledform ready for use. As is therein shown, the grinding wheel 14 having afirst surface 13 and a second or top surface 17 has the barrel 20 of thenut 12 inserted through the opening 15 therein. As is illustrated, aportion of the threads 38 on the outer surface of the barrel 20 protrudethrough the opening 15 and extend beyond the surface 17. The supportunit 10 is then secured to the abrasive wheel 14 by mating the threads49 formed in the bore 48 with the threads 38. The support unit is handtightened through the facility of the knurling 28 on the body 26 so thatthe wheel 14 is snugly trapped between the surface 18 of the flange 22and the surface 46 of the support unit 10. Thereafter the assembledwheel and reusable mount are brought into engagement with the threadedshaft or spindle of a power tool. As is illustrated, the threaded shaft70 of a power tool (not shown) is threadably engaged with the threads 34in the bore 32 of the nut 12. A shoulder 74 formed on the power toolshaft 72 engages the wear or bearing surface disposed upon the firstface 44 of the body 42 of the support unit 10. It should be understoodthat the shaft 70 may be part of a powertool or alternatively be a shaftthat is received within a collet or chuck of a powertool. The diameterof the body 42 of the support unit 10 and the flange 22 of the nut 12are substantially the same and thus the surface 46 of the support unitengaging the surface 17 of the wheel 14 provides adequate support forthe wheel during use except when very large (5 inches in diameter orlarger) wheels are used.

It should be recognized that when the grinding wheel 14 assembled withthe reusable mount of the present invention, as shown in FIG. 4, isplaced in use by the rotary power tool there will be very littlerelative movement between the nut 12 and the support unit 10. Suchresults because the engagement of the threads 38 on the nut barrel andthe threads 49 on the support unit lock these two elements together andprevent vertical movement there between (as viewed in FIG. 4) eventhough an upward force is applied to the nut 12 by the threadedengagement with the threaded shaft 70 on the power tool. The force isabsorbed by the bearing surface 30 and the body 42 of the support unit10. In the event that wheel 14 rotates when grinding starts, the nut 12may rotate slightly to lock the wheel in place. At most, such rotationwill be only a few degrees. When use is completed and the grinding wheel14 is to be discarded, it may be easily removed from the threaded shaft70 of the power tool 72 simply by gripping the remaining portion of thegrinding wheel 14 and turning it in a counter clockwise directionwithout the use of tools of any type. The construction of the reusablequick change mount of the present invention provides immediate and easyrelease from the power tool 72 whereupon the nut and support unit may bethreadably separated for reuse and the spent grinding wheel 14discarded.

By reference now to FIG. 5, there is shown in cross sectional view acut-off wheel 76 assembled between a nut 78 and a support unit 80 in themanner above described by inserting the threaded barrel 82 of the nut 78through the opening 84 in the cut-off wheel and threadably attaching thesupport unit 80 thereto to capture the cut-off wheel 76 between thesupport unit 80 and the nut 78. The barrel has an enlarged diameterportion 87 at its lower end adapted to snugly be received within theopening in the cut-off wheel. An internally threaded spindle on acut-off tool (not shown) threadably engages the thread on the outersurface of the barrel 82 of the nut 78. The end of the spindle will bearagainst the surface 86 on the top of the support unit 80.

Referring now more particularly to FIG. 6, there is illustrated in crosssection a support unit for use with large grinding wheels or otherabrasive devices. Such devices require more support than can be providedby the support unit above shown and described. As is illustrated in FIG.6, the support unit 90 includes a body 92 having first and second ends94 and 96 respectively. A bearing 98 is inserted in the end 96. The body92 is turned down or milled to reduce its diameter as shown at 100 toprovide a shoulder 102. A flange 104 having a central opening 106 isdisposed abutting the shoulder 102. The end 94 of the body is thenstamped or swaged to form a bead or ring 108 of metal to loosely securethe flange 104 to the body 92 of the support unit 90. Such anarrangement reduces friction when the body 92 of the support unit 90 isthreaded secured to the threaded barrel of a nut to secure the reusablemount to an abrasive device. That is, when the flange 104 contacts theabrasive device the body 92 can continue to rotate without rotation ofthe flange.

Referring now more particularly to FIG. 7 there is illustrated incross-section an alternative embodiment of a support unit also for usewith large grinding wheels or other abrasive devices. It has been foundthat with the depressed center grinding wheels 5 inches in diameter orlarger, that there may be large variations in the height of the top ofthe depressed center wheel relative to the surface 17 of the wheel frommanufacturer to manufacturer. Under some circumstances, the height ofthe top of the depressed center wheel is such that when the structure asused in FIG. 6 is utilized, the bottom surface of the flange willcontact the back of the wheel prior to the surface 94 of the body 92 ofthe support unit contacting the top of the depressed center. When suchoccurs then under extreme use, there is a tendency for the depressedcenter wheel to turn in the mount. Although this does not create anyparticular problem insofar as safety is concerned, it is not a desirablesituation. It therefore was found to become necessary to provide anadjustable height contact flange and such is provided in the structureillustrated in FIG. 7. As is therein shown, a support unit 110 includesa body 112 having a first surface 114 and a second surface 116. Thebearing surface 118 is provided in the manner as above described. A stopring 124 is positioned over the outside of the body 112 immediatelyproximate the upper surface 116. After the stop ring 124 is thuspositioned, the top surface 116 is upset or staked to rigidly andnon-detachably affix the stop ring 124 to the body 112. As isillustrated in FIG. 7, the external surface of the body 112 is providedwith threads 118 extending from a point immediately below the stop ring124 to a point 120 intermediate the stop ring 124 and the bottom surface114. A base ring 122 is threadably attached to the threads 118. As wasdescribed previously with regard to FIG. 6, the flange 104 is positionedupon the outer surface of the body 112 and is then secured in place bystaking to provide the bead or ring 108.

It should now be recognized by those skilled in the art that when adepressed center grinding wheel is assembled in place through theutilization of a nut being inserted through the opening therein and thenbeing secured to the support member 110 by way of the threads 126disposed internally thereof the surface 128 of the flange 104 willengage the back of the depressed center wheel causing the flange to moveupwardly as viewed in FIG. 7 until the surface 114 of the body 112engages the top of the depressed center wheel. When such occurs, thebase ring 122 is then rotated downwardly until it engages the topsurface 130 of the flange 104 immediately adjacent the outer surface ofthe body 112. The base ring 122 is then secured snugly by hand thus,clamping the abrasive grinding wheel between the support unit and theflange on the nut as above described.

As above described, the abrasive finishing wheel along with the mount isthen secured upon the spindle or arbor of the power tool for use in thetraditional manner. When use is completed, the user may grasp the wheeland remove the unit along with the mount from the power tool after whichthe base ring 122 is loosened by turning the same in a counter clockwisedirection allowing the wheel to be removed and discarded while retainingthe nut and support unit 110 for future use.

There has thus been disclosed a reusable a reusable quick change mountfor use with abrasive devices which may be quickly and easily assembledon the abrasive device and easily and quickly removed when the device isto be discarded after use, after which, the mount may be reused with yetan additional or different abrasive device.

1. A reusable quick change mount for use with abrasive devices (14)having first (13) and second (17) surfaces and having a central opening(15) therethrough and adapted for rotation by a rotary power toolcarrying threads (70), said mount comprising: (a) a nut (12) having abarrel (20) carrying threads formatting with the threads carried by saidpower tool and having an outer surface (36), said barrel having first(24) and second ends; (b) a first flange (22) extending radially outwardat said first end of said barrel; (c) said barrel being adapted to bereceived in said central opening of said abrasive device with a portionof said flange engaging said first surface thereof and a portion of saidbarrel including said second end extending beyond said second surfacethereof; (d) said outer surface of said barrel being threaded (38) overat least that portion extending beyond said second surface; (e) asupport unit (10) having a body (42) defining a first bore (48)centrally disposed therethrough, said first bore having threads (49) formating with the threads on said outer surface of said barrel; and (f)said threads on said outer surface of said barrel and in said firstbore, when engaged, operate to capture said abrasive device between saidfirst flange and said support unit and operatively clamp said abrasivedevice for rotation by said power tool, the position of said supportunit with respect to said nut, after assembly by hand on said abrasivedevice, remaining substantially unchanged during use thereby enablingremoval of said support unit from said nut by hand after use to replacesaid abrasive device.
 2. A reusable quick change mount as defined inclaim 1 wherein said support unit body includes first (44) and second(46) faces, said first face being disposed away from said second surfaceof said abrasive device when assembled thereon, said first face furtherincluding a bearing surface (30) surrounding said first bore forengaging said power tool.
 3. A reusable quick change mount as defined inclaim 2 wherein said bearing surface on said first face is a heattreated steel material.
 4. A reusable quick change mount as defined inclaim 2 wherein said bearing surface is a hard plastic material.
 5. Areusable quick change mount as defined in claim 2 wherein said bearingsurface is a washer shaped material secured to said support unit.
 6. Areusable quick change mount as defined in claim 1 wherein said nutdefines a second bore (32) centrally disposed therethrough, said secondbore carrying said threads (34) disposed on said barrel.
 7. A reusablequick change mount as defined in claim 6 wherein said nut and firstflange are formed from a unitary member.
 8. A reusable quick changemount for use with abrasive devices (14) having first (13) and second(17) surfaces and having a central opening (15) therethrough and adaptedfor rotation by a rotary power tool carrying threads (70), said mountcomprising: (a) a nut (12) having a barrel (20) having an outer threadedsurface (36) and defining a first threaded bore (32) centrally disposedtherethrough, said barrel having first (24) and second ends, saidthreads in said first bore mating with the threads carried by said powertool when said abrasive device with said quick change mount assembledthereon is mounted upon said power tool; (b) a first flange (22)extending radially outward at said first end of said barrel; (c) saidbarrel being adapted to be received in said central opening of saidabrasive device with a portion of said first flange engaging said firstsurface thereof and a portion of said barrel including said second andextending beyond said second surface thereof; (d) a support unit (10)having a body (42) having first (44) and second (46) faces, said bodydefining a first threaded bore (48) centrally disposed therethrough,said first threaded bore (48) matingly engaging said threaded outersurface of said barrel; (e) said threads, when matingly engaged, andwhen said abrasive device is being used, function to operatively clampsaid abrasive device between said first flange and said second face ofsaid support unit, the position of said support unit with respect tosaid nut, after assembly by hand on said abrasive device, remainingsubstantially unchanged during use thereby enabling removal of saidsupport unit from said nut by hand after use to replace said abrasivedevice.
 9. A reusable quick change mount as defined in claim 8 whereinsaid support unit first face being disposed away from said secondsurface of said abrasive device when assembled thereon, said first facefurther including a bearing surface (30) surrounding said first forengaging said power tool.
 10. A reusable quick change mount as definedin claim 9 wherein said bearing surface on said first face is a heattreated steel material.
 11. A reusable quick change mount as defined inclaim 9 wherein said bearing surface is a hard plastic material.
 12. Areusable quick change mount as defined in claim 9 wherein said bearingsurface is a washer shaped material secured to said support unit.
 13. Areusable quick change mount as defined in claim 8 which further includesa second flange (104) extending outwardly from said support unitadjacent said second surface thereof for engaging said second surface ofsaid abrasive device.
 14. A reusable quick change mount as defined inclaim 13 wherein said second flange is rotational with respect to saidsupport unit body.
 15. A reusable quick change mount as defined in claim14 wherein said support unit includes an outer threaded surface (118)and a base ring (122) threadably supported thereon.
 16. A reusable quickchange mount as defined in claim 15 wherein the threads on the outersurface intermediate said first and second faces such that said secondflange is vertically movable with respect to said support unit body. 17.A reusable quick change mount as defined in claim 16 which furtherincludes a stop ring (124) extending outwardly from said body adjacentsaid first face.
 18. A reusable quick change mount as defined in claim17 wherein said stop ring is seated onto said threaded outer surface ofsaid body and then non-detachably secured thereto.